The purpose of my thesis research has been to understand the formation of mitotic chromosome structure by using chromosome micromanipulation. Folding mitotic chromosomes from their loose interphase form into their individualized, compacted form is required for easy handling of the chromosomes for cell division. This process is facilitated by several...
Protein homeostasis, or proteostasis, is essential for preserving all cellular functions and involves a balance of protein synthesis, folding, trafficking, and degradation. A collapse in proteostasis is a common feature of many neurodegenerative disorders that are characterized by the accumulation of insoluble protein aggregates in the brain. Parkinson’s disease (PD)...
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease, affecting children and adults. Chemotherapy regimens show high response rates but have debilitating effects and carry risk of relapse. Until now, no targeted therapy has been approved. In addition, 40% of patients will relapse and their treatment options are limited because...
Parasitic nematode infections are common in both humans and livestock populations around the globe. In humans, these infections cause illness which can be debilitating. In livestock, parasitic nematode infections result in poor animal health and wellbeing as well as decreases in the yield of these animals. The decrease in yield...
The treatment of AML remains to be a challenge due to the high rates of resistance and relapse experienced by patients after initial therapy. The MAPK-interacting kinases 1 and 2 (MNK1/2) have generated increasing interest as therapeutic targets for AML due to their critical role in malignant hematopoietic transformation via...
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by motor neuron (MN) degeneration and resulting in progressive paralysis and death. ALS is genetically heterogeneous, disease pathophysiology is not completely understood, and there are no effective drug therapies. To develop broadly applicable therapeutics, we examine disease mechanisms in the...
Mitochondria-lysosome contacts are recently identified sites for mediating crosstalk between both organelles, but their role in normal and diseased human neurons remains unknown. We used super-resolution and live-cell microscopy in human iPSC-derived neurons to demonstrate that mitochondria-lysosome contacts can dynamically form in the soma, axons, and dendrites of human neurons,...
Symbiotic relationships involve a life-long interaction between host and bacteria, and there is much we do not understand about how these interactions are developed and maintained. During the horizontal recruitment of beneficial bacteria by hosts, a complex set of molecular signals and communication ensures specificity. On the bacterial side, these...
Cytokines made by macrophages play a critical role in determining the course of Legionella pneumophila infection. Prior, murine-based modeling indicated that the cytokine response initiated upon recognition of L. pneumophila involves a subset of Toll-like receptors, namely TLR2, TLR5, and TLR9. Using shRNA/siRNA knockdowns and subsequently CRISPR/Cas9 knockouts (KO), I...
In nearly all Eukaryotes, the membrane-enclosed nucleus contains the vast majority of the cellular genome. Within this sub-cellular compartment, the nuclear architecture facilitates genomic chromatin organization. Controlling chromosomal loci’s spatial positioning relative to subnuclear structures and each other can have local and global effects on gene expression. Moreover, chromatin organization...
Regulatory RNAs are found throughout nature controlling critical cellular processes and enabling cells to sense and respond to their environment. In order to provide genetic regulation, these RNAs can selectively bind to target molecules, proteins, and invading pathogens, all while modulating gene expression on both the transcriptional and translational level....
Prions are self-perpetuating, alternative protein conformations associated with neurological diseases and normal cellular functions. Saccharomyces cerevisiae contains many endogenous prions – providing a powerful system to study prionization. Previously, the Li Lab demonstrated that Swi1, a component of the SWI/SNF chromatin-remodeling complex, can form the prion [SWI+]. A small region,...
Transcription of nucleic acids (DNA and RNA) is a hallmark of life, taking the information stored within genomic nucleic acids and converting it into a form that is useful for producing the proteins necessary for cellular and organismal function. In eukaryotes, transcription of DNA into messenger RNA (mRNA) requires the...
When properly regulated, inflammation leads to the recruitment and activation of circulating leukocytes to maintain and restore tissue homeostasis. Although this process is critical for successful wound healing and the elimination of pathogens and infections, misdirected inflammation can exacerbate pathology and cause substantial morbidity and mortality. Inflammation a fundamental process...
The insulin/Insulin-Like Growth Factor (IGF) pathway is essential for linking nutritional status to growth and metabolism. MicroRNAs (miRNAs) are short RNAs that are players in the regulation of this process. The miRNA miR-7 shows highly conserved expression in insulin-producing cells across the animal kingdom. However, its conserved functions in regulation...
The evolutionarily conserved COMPASS family of methyltransferases implements histone H3 lysine 4 (H3K4) methylation, an epigenetic mark associated with transcriptional activation. Given the high mutational prevalence of COMPASS subunits across cancers and neurodevelopmental disorders, understanding COMPASS function would lend important insights into disease pathogenesis to facilitate development of effective therapies....
Uterine leiomyomas (fibroids) are a major source of gynaecologic morbidity in reproductive age women and are characterised by the excessive deposition of a disorganised extracellular matrix, resulting in rigid benign tumours. Clinically, leiomyoma patients usually present with pelvic pain, urinary incontinence, as well as heavy cyclic and non-cyclic bleeding. Curative...
Although centrosomes nucleate and organize microtubules in mitotically-dividing cells, spindles in female reproductive cells (oocytes) form in their absence. In some organisms acentrosomal spindle assembly is mediated by acentriolar microtubule organizing centers (MTOCs) that are thought to functionally replace centrosomes. However, spindle assembly in human oocytes does not require MTOCs;...
Heart failure due to genetic cardiomyopathy is associated with a range of phenotypic expression. The studies in this body of work interrogated the role of noncoding variation in modifying cardiomyopathy phenotypes. We used cap analysis of gene expression in heathy and failed left ventricles to define the regulatory environment of...
This dissertation focuses on the development of quantitative approaches for characterizing endogenous signaling pathways and designing new pathways in mammalian cells. I demonstrate how mathematical descriptions that are formulated to explain gene expression patterns can also serve as a powerful springboard for deeper analyses into the properties and functions of...